Membrane pump with ventilation valve

Technical field [0001] The invention relates to a suction pump with a vent valve according to the preamble of claim 1.

Background Art [0002] Suction pumps are known for a variety of applications. However, they can be used especially in breast pumps for expressing breast milk or as medical mammals for aspiration of body fluids.

[0003] There are suction pumps in closed systems that pump the same air in the working chamber. However, open systems with a venting valve, which can be opened cyclically by means of an electromagnet, are also known.

[0004] The requirements for these suction pumps, especially when used as breast pumps, are relatively high. So they should be as efficient as possible and yet be relatively small. Particularly when used as a breastpump, they should also be maintenance-free and easy to clean as far as possible.

[0005] US 4 886 494 discloses a suction pump with a membrane plate. An inlet and outlet flap as well as a vacuum membrane are integrated in this membrane plate. In addition, it has a valve seat for the vent valve.

[0006] US 6 090 065 describes a suction pump with a vacuum membrane and a pusher that acts on a membrane plate independent of the vacuum membrane.

Presentation of the invention [0007] the object of the invention is to create a suction pump that can be assembled as simply as possible.

[0008] This task is solved by a suction pump having the features of claim 1.

[0009] The suction pump according to the invention has a breather valve with a breather membrane, the breather membrane and the vacuum membrane used to create the vacuum being made as one element in the form of a common membrane plate. [0010] Due to the fact that the breather valve and the vacuum membrane are located on the same board, these elements are cheaper to manufacture and simpler to install.

[0011] In a preferred embodiment, the pump has an upper housing segment, a central housing segment and a lower housing segment, with the membrane plate and the valve plate respectively located between the housing segments. Thanks to this division, it is possible to realize more elements on the same part. In particular, the vacuum membrane necessary to create a vacuum and the venting membrane necessary for rapid removal of the vacuum can be made as one element on the same part. Also adjustable flaps or valve flaps can be made as one element on the same part. The electric motor and solenoid can be mounted in the same housing segment. By dividing the pump into several, preferably five levels, the number of parts can be reduced to a minimum without sacrificing the complexity of the pump set design. This not only reduces the external dimensions of the pump set, but also minimizes production and assembly costs.

[0012] Another advantage of this modular construction with several levels is that the pump can be cleaned by simply flushing without having to disassemble it. Thanks to the discharge outside, a sponge becomes unnecessary. Such sponges are used in the art to collect milk sucked into the pump and also to suppress the sound. However, they need space in the pump and tend to emit unwanted odors.

[0013] Preferred forms of implementation of the suction pump allow the pump to be as small as possible, yet allow short cycle times.

[0014] In this preferred embodiment, the venting element that closes the venting opening of the venting valve is only partially lifted from the beginning. Due to this, less force is needed than when the entire vent hole is opened in one move.

[0015] The means used to actuate, in particular to raise the venting element may therefore have less power and may therefore have smaller dimensions. If an electromagnet is used as such, then a low power unit can be used. This is because the electromagnet when pulling in or out. lifting the breather may initially spend less force than at the end of the movement. This smaller force initially available is enough to reveal the smaller hole. Thus, a relatively small and therefore more affordable electromagnet can be used. For this, a relatively large vent hole can be formed. This ensures rapid elimination of the vacuum and, as a result, the desired pump functionality.

[0016] The pump easily achieves 120 cycles per minute. However, even with 50-72 cycles per minute, it can be used optimally. One number of cycles is particularly suitable for stimulation, the other for expressing breast milk.

[0017] In a preferred variant of the above-mentioned embodiment, only the edge area of ​​the vent element is removed from the vent hole. A minimum force is needed when this edge area coincides with the corner of the venting element.

[0018] The venting element is a membrane. Lifting its edge area is facilitated when the raised edge area is thinner than the remaining membrane. Preferably, the vent hole is formed as a polygon, preferably a quadrangle or triangle. Also, the membrane is preferably formed as a polygon, preferably a quadrangle or triangle.

For easier lifting of the membrane, a connecting pin can be attached to it (or it can be formed as an integral part thereof) connected to the lifting magnet anchor. Preferably, this connecting pin is located in the edge region of the membrane covering the vent opening. However, it is possible to create a membrane with an elevated flange, the connecting pin being located not above the vent hole, but with the elevated flange.

[0020] If the connecting pin is formed movably with respect to the membrane, the tolerances resulting from production or assembly can be controlled. The angular deviations of the electromagnet can also be compensated. Good results have been achieved using a connecting pin, which is formed of silicone as an integral part of the breather membrane and which has sufficient rigidity by appropriate thickening of the material. It can be articulated. In a simple implementation, however, the elasticity of the material of the connecting pin is sufficient to shape it movably relative to its mounting location.

[0021] The abovementioned embodiment with a venting membrane actuated in the peripheral region has the advantage that it ensures tightness and therefore, especially when used in a breastpump, it must not have leaks for the pumped milk.

[0022] Another advantage of the abovementioned forms of implementation, especially when using membranes, is that no springs are needed and thus the amount of parts needed can be reduced. Since no springs need to be fitted, the work involved in installing the pump is also reduced.

[0023] In another preferred embodiment, the suction pump has a safety valve, the suction pump cannot be immobilized by a liquid, especially milk that has been sucked into the pump and has deposited there. [0024] This suction pump has a safety valve having a first stage, which opens at the first vacuum, and a second step that opens at the second vacuum. The first vacuum is lower than the second.

[0025] This two-stage safety valve design prevents milk from entering the second stage. Since the first stage opens even with a very slight deviation from the ideal negative pressure, in the event of sticking at a higher negative pressure, i.e. in an emergency, it will still open. The second valve prevents the entire safety valve from being opened when the deviation is too small, but it opens reliably in an emergency.

[0026] The suction pump according to a preferred embodiment can thus eliminate the vacuum without a great deal of effort in a relatively short time. The suction pump according to the invention is suitable for a wide range of applications. It is especially useful as a breast pump for breast milk suction and as a medical mammal for suctioning body fluids. The pump assembly according to the invention is particularly suitable for use in a mobile suction device, as described in particular in WO 2004/069306 (Application number PCT / CH 2004/000061).

[0027] Further advantageous embodiments arise from the dependent claims.

Brief Description of the Drawings [0028] The subject of the invention is explained below based on the preferred embodiments shown in the accompanying drawings, in which Figure 1 shows a perspective view of a suction pump according to the invention without an outer casing;

2 is a bottom view of the suction pump according to FIG. 1;

Figure 3 is a longitudinal section through the suction pump of Figure 1;

Figure 4 is an exploded view of the suction pump of Figure 1;

Figure 5 is a perspective view of the lower segment of the suction pump housing according to Figure 1;

Fig. 6 is a top view of the suction pump membrane plate according to Fig. 1;

Figure 7 is a longitudinal section through the membrane plate of Figure 6;

Fig. 8 is an enlarged section of the membrane plate according to Fig. 7;

Figure 9 is a top view of one part of the upper housing segment;

Figure 10 is a top view of the suction pump membrane plate according to a second embodiment; Figure 11 is a longitudinal section through the membrane plate according to Figure 10 and Figure 12, an enlarged section of the membrane plate according to Figure 11.

Roads for carrying out the invention [0029] In Fig. 1 the suction pump according to the invention is shown in a form in which it is particularly suitable for a breast pump for expressing human breast milk. However, the pump is also suitable for other applications, for example medical mammals for suctioning body fluids.

[0030] Only an effective pump set is shown. This aggregate is usually placed in an external housing. This external housing as well as the electronics necessary to start the pump and any energy source such as a rechargeable battery or battery are not shown.

[0031] A pump built in an extremely compact manner. One of its largest components is the electric motor 1. In addition, it has an upper, middle and lower housing segment 2, 4, 6, which can be assembled together by sliding. In addition, there is a connector 7, which is part of these housing segments or, as is the case here, is also connected to them by the insertion method.

[0032] At the connector 7 there is at least one funnel connection 70 on the funnel side on which the connection hose to the funnel can be clogged. Furthermore, the connector 7 has an outlet 71. This outlet 71 also extends beyond the outer casing. In addition, there is also the vent channel 72 protruding from the outer casing and spacers 73. Spacers 73 keep the pump set away from the outer casing so that vibration cannot be transmitted and sufficient sound insulation is provided.

[0033] Fig. 2 shows how individual connectors 70, 71, 72 connect through individual channels to individual areas of the pump.

[0034] The longitudinal section through the pump, shown in Fig. 3, now without motor 1, shows that the pump, despite its compactness, is divided into three different functional areas: pump module P, venting module V and the safety module S placed between them. The structure of the pump is best readable with the assembly of Figures 3 and 4. [0035] The pump module P has a vacuum membrane 31 and inlet and outlet adjusting flaps 51, 52, which together with the inlet and outlet 62, 63 or with the opening of the pump working chamber 43 'they form a connection between the working chamber of the pump 43 and the vacuum channel 69. The vacuum diaphragm 31 connects via a connecting rod 11, a connecting element 12, e.g. a ball bearing, and an eccentric 13 with the drive shaft 10 of the electric motor 1 and can be with this motor 1 raised and lowered according to the set or determined freely by the control system rhythm or pump characteristics.

[0036] The venting module V has a venting valve with a venting membrane 32 and a vent tightly closed by the hose in the form of a venting diaphragm seat 44. The chamber 44 'surrounding the venting diaphragm seat 44 is connected via a venting connection 45 to a venting channel 72. Venting diaphragm seat 44 is open downwards, i.e. towards the side away from the venting membrane 32, and connects to the first venting hole 54 of the valve plate 5 and the second venting hole 67 of the lower housing segment 6. This second venting hole 67 connects via a vacuum channel 69 to the safety valve chamber 68 and inlet 62.

[0037] The venting membrane 32 is connected via a connecting pin 33 to the anchor 80 of the lifting magnet or solenoid 8. The solenoid 8 lifts the venting membrane 32 and thus reveals the seat of the venting membrane 44. As a result, air enters through venting channel 72 and the first and second holes vent 54, 67 to the vacuum channel 69, and the underpressure therein is eliminated. This raising and lowering of the venting membrane 32 also takes place according to a function set or selected freely by means of a control installation coordinated with the movement of the vacuum membrane 31. Preferably, the movements of the vacuum membrane 31 and the venting membrane 32 are coordinated so that the pump characteristics as described are obtained. in WO 01/47577 and how it is adapted to the needs of the mother and child, or mimics the baby's natural sucking rhythm. The aggregate functions in any position, i.e. lying on the table or standing or during transport. The vacuum created is largely independent of how the aggregate is located in space.

[0038] The safety module S has a safety valve. This safety valve ensures that in the event of incorrect operation or failure of the control electronics, which coordinates the movements of the vacuum membrane 31 and the venting membrane 32, the size of the vacuum in the pump did not increase excessively and did not damage the mother's breast.

[0039] The safety module S is according to the invention constructed in two stages. The first stage consists of a first safety diaphragm 55 and a hemispherical safety valve 46 with a small lateral opening 46 'which presses on the first safety diaphragm 55. This first stage opens already at low vacuum of ca 120 mm Hg.

[0040] The second stage has a second safety membrane 35, which is closed by means of an adjusting screw 9. The limit value at which it opens can be changed by adjusting the adjusting screw 9. According to the invention, it opens at a higher negative pressure than the first stage, for example at ca 290 mm Hg.

[0041] Therefore, if milk or other sucked liquid enters the pump in an undesirable way, it will deposit in the first stage area and will not be able to enter through the chamber lying between the second stage. It can therefore seal the first safety membrane 55 at most. This one, if sealed, may not open at the set value, but it still does so early enough to allow unloading. The second diaphragm always opens only if the limit value is actually exceeded and the pump must be relaxed. Since the second stage cannot be soiled, it always opens reliably.

[0042] The individual parts of the pump are best seen in Fig. 4. This exploded view shows that the pump is divided into several levels I, II, III, IV, V, with the parts of the pump module P, safety module S and venting module V each time placed on common levels.

[0043] The first level I, which in working position usually, but not necessarily, creates the highest level, has an upper housing segment 2, the aforementioned motor 1 as well as an electromagnet 8. The motor 1 is attached with fastening screws 21 to the upper segment motor plate 20 enclosures 2. The motor can be screwed to the motor plate 20, as well as connected by sliding it into the pump set. Housing segment 2 has a connecting rod chamber 23 that serves for connecting rod 11, ball bearing 12 connected to it, and eccentric with counterweight 13. Counterweight 13 is not indispensable. The upper housing segment 2 furthermore has a magnet chamber 24 separate from the connecting rod chamber 23, in which the electromagnet 8 is mounted. At the lower end, the upper housing segment 2 has upper latch tongues 22 which protrude downwards.

[0044] In the upper housing segment 2, the adjusting screw 9 is further movably arranged for the second stage of the safety valve.

[0045] The second level II is defined by a membrane plate 3 that extends at least approximately over the entire base surface of the upper housing segment 2 and thus the pump set. The membrane plate 3 is made of a flexible material, preferably silicone, and is relatively thin. It has centering 30 holes in the edge region and top or lower sealing lips 34, 34 ', 34 ", which provide air and fluid tight connection to the upper housing segment 2 or to the middle housing segment 4. The lower sealing lips are recognizable in Fig. 7. The membrane plate 3 includes a breather membrane

32, which is in the form of a triangle. The venting membrane 32 has, as shown in Fig. 6, a triangular basic form. This triangle is divided into two sub-areas, where the first sub-area 32 'again forms a triangle and the second sub-area 32 "is formed by the remainder of the membrane and thus has a trapezoidal form. The first corner of the first sub-area 32' coincides with the corner of the vent membrane 32. The opposite side of the first sub-area 32 'runs parallel to the opposite side of the vent membrane 32 and the other two sides of the triangle of the first sub-area 32' coincide with the sides of the triangle of the vent membrane 32. The triangular first sub-area 32 'has a smaller thickness than the second.

[0046] Subarea 32 ", as seen in Figures 7 and 8.

[0047] In the free corner of the first sub-area 32 ', a connecting pin 33 is formed. It projects, as can also be seen in Figures 7 and 8, at least approximately vertically up the membrane plane upwards and is permanently connected to the anchor 80. The venting membrane 32 is surrounded by a first sealing lip 34.

[0048] The membrane plate 3 further includes a vacuum membrane 31 which is connected to the connecting rod 11. The connecting rod 11 can be formed by thickening the material as an integral part of the vacuum membrane 31 or be made of a two-component material. However, it can also be made separately and connected to the membrane 31 during assembly. The vacuum diaphragm is sealed with a second sealing lip 34 'to the upper and middle housing segment 2, 4.

[0049] Furthermore, the membrane plate 3 has a second safety valve membrane 35. This has, as can best be seen in Fig. 7, an opening widening downwards in the form of the letter "v" and is sealed by means of the surrounding third sealing lip 34 "relative to the upper and middle housing segment 2, 4.

[0050] The third level III forms the middle housing segment 4. This is made like the upper and lower housing segment 2, 6 preferably of solid plastic, for example POM (polyoxymethylene). The middle segment of the housing 4 has the form of a plate and has a flat upper and flat bottom surface. On its side surfaces it has upwards or downwards, the latch latches 40, 41, wherein the upper latch latches 40 engage in the upper latch tongues of the upper housing segment 2 and the lower latch latches 41 in the lower latch tongues 60 of the lower housing segment. In addition, there are still centering holes 42 that line up with the centering holes 30 of the membrane plate 3.

[0051] In the central housing segment 4 there are two closed down hollows with small lateral connection holes. One of these hollows forms a vacuum diaphragm seat 43 for a vacuum diaphragm and thus defines the pump working chamber. The second of these hollows forms a first level safety valve 46. In addition, in the middle segment of the housing 4 there is a chamber 44 'with a membrane seat 44 located therein for the venting membrane 32. This socket 44 has a triangular form in this example. The chamber 44 'is a h-shaped cavity, the cavity being connected to a vent connector 45.

[0052] The fourth level IV consists again of a flexible plate, preferably of silicone. It consists of a valve plate 5. Also this one has centering holes 50, at least several of these centering holes 50 are in line with the centering holes of the middle housing segment 4 and the membrane plate 3.

[0053] The valve plate 5 has a first adjustment flap 51 that forms an inlet to the vacuum chamber. It also has a second adjustment flap 52 that forms a projection from the vacuum chamber. A double sealing lip 53 leads from the second adjustment flap 52, which surrounds the connection channel 64 located in the lower housing segment 6 and open upwards and seals it from above.

[0054] The first diaphragm 55 of the safety valve is further formulated to the valve plate 5. In addition, there is a first vent hole 54 that provides a connection between the vent membrane seat 44 and a second vent hole 67 which is located in the lower housing segment 6. The individual elements of the valve plate 5 again have lower and upper sealing lips to seal the middle and lower housing segments 4, 6. Preferably, all the elements of the valve plate 5 are made as one element together with it.

[0055] The fifth level V comprises a lower housing segment 6 and a connector 7. These two parts can be implemented as one common part or, as shown here, be coupled together by means of plug-in connections.

[0056] The lower housing segment 6 is shown in Fig. 4 and in a different perspective in Fig. 5. It is also plate-shaped, with its bottom side forming the bottom of the pump set. On the sides, the lower latch tongues 60 protrude upwards, so that the lower latch latches 41 of the middle housing segment 4 can nest in them. In addition, there are centering pins 61 which also protrude upwards and which can pass through the centering holes 30, 42, 50 of the membrane plate 3, the middle housing segment 4 and the valve plate 5. These centering pins and centering holes facilitate the overlap of individual levels and allow in this way quick assembly.

[0057] The lower housing segment 6 further has a first circular hollow with a central elevation that forms the inlet opening 62. The second circular hollow forms the outlet opening 63. This inlet opening 62 is connected to the vacuum channel 69 running inside the lower housing segment 69. This channel 69 first passes through the opening of the safety valve 68, which is also made as a recess and above which the first stage safety membrane 55 is arranged.

[0058] The connection channel 64, which being open at the top and sealed by the sealing lip 53 extends in the lower housing segment 6, exits through the outlet opening 63. This connection channel 64 is connected to the second ventilation opening 67 in the lower housing segment 6. 5, the connecting channel 64 ends in a blow connection 66 that can be plugged into blow 71. A second vent hole 67 leads to a connector 65 located on the funnel side, which is connected to the connection stub 70 located on the funnel side.

[0059] This design allows simple cleaning of the pump. If milk or other sucked liquid enters the pump, it can be easily flushed with water or air in such a way that the cleaning medium is introduced under pressure or blown through the connector 70 on the side of the suction pump, leaving the pump through vent channel 72 and blowing out 71.

[0060] Fig. 9 is a partial top view of the upper housing segment 2. As can be seen here, the setting screw 9 of the safety valve S has a circular cross section, but is screwed into a threaded hole 25 with a square cross section. As a result, a sufficiently large air flow is always ensured. [0061] Figs. 10 to 12 show a second embodiment. This form of implementation differs from the scope of the breather valve described above. The other parts remain identical and are therefore not depicted and described here again. In this example, the venting membrane 32 has a non-triangular but a quadrangular shape. However, it can also have a hexagonal or octagonal shape. In practice, however, it turned out that the quadrangular variant closes and opens with greater certainty compared to the triangular form. The venting membrane is again divided into 32 ', 32 "thick and thin subarea, the connecting pin 33 is located at the thin 32'. Both these 32 ', 32" subareas also have a substantially quadrangular shape, with the connecting pin 33 being located at the longitudinal side of the thin sub-area 32 'away from the thick sub-area 32 ". It is no longer fixed in the corner, but more or less in the middle of this longitudinal side, as shown in Fig. 10. It has also been shown that better functionality is provided when the connecting pin is formed to the side wall 44 "of the chamber 44 'as shown in Figure 12. The hole below, i.e. the seat of the vent membrane 44, however, still has a preferably triangular form. In this case, the connecting pin 33 is preferably located exactly above the corner of the triangular opening 44.

[0062] The suction pump according to the invention therefore has many advantages. It offers great functionality in a minimal space, and it is cheap to produce and easy to install.

List of markings [0063]

P pump module

V venting module

S security module

And the first level

II second level

III third level

IV the fourth level

V fifth level engine drive shaft connecting rod ball bearing eccentric counterweight upper housing segment engine plate mounting screws upper latch tongues connecting rod chamber magnet chamber threaded hole membrane plate centering hole vacuum membrane venting membrane

32 'first subarea

32 "second sub-area connecting the first sealing lip

34 'second sealing lip

34 "third sealing lip second diaphragm safety valve 4 middle housing segment 40 upper latch latches 41 lower latch latches 42 centering hole vacuum diaphragm seat

43 'opening of the working chamber of the pump venting diaphragm seat

44 'chamber

44 "sidewall venting first stage safety valve

46 'side hole valve plate centering hole first adjusting flap second adjusting flap sealing lip connecting channel 54 first vent hole 55 first diaphragm safety valve 6 lower housing segment lower latch tongues connecting pin inlet outlet outlet connection connecting channel outlet connector second outlet vent hole safety valve chamber vacuum channel connector connecting piece on the extraction side blow-out vent channel spacers magnet lifting anchor adjusting screw

VP / 1114 / RW

EP 2 105 151 B1